Calling the XrmMergeDatabases function
is equivalent to calling the XrmCombineDatabase function with an override
argument of True.

The XrmCombineDatabase function merges the contents
of one database into another. If the same specifier is used for an entry
in both databases, the entry in the source_db will replace the entry in
the target_db if override is True; otherwise, the entry in source_db
is discarded. If target_db contains NULL, XrmCombineDatabase simply stores
source_db in it. Otherwise, source_db is destroyed by the merge, but the
database pointed to by target_db is not destroyed. The database entries
are merged without changing values or types, regardless of the locales
of the databases. The locale of the target database is not modified.

The
XrmCombineFileDatabase function merges the contents of a resource file
into a database. If the same specifier is used for an entry in both the
file and the database, the entry in the file will replace the entry in
the database if override is True; otherwise, the entry in the file is
discarded. The file is parsed in the current locale. If the file cannot be
read, a zero status is returned; otherwise, a nonzero status is returned.
If target_db contains NULL, XrmCombineFileDatabase creates and returns
a new database to it. Otherwise, the database pointed to by target_db is
not destroyed by the merge. The database entries are merged without changing
values or types, regardless of the locale of the database. The locale of
the target database is not modified.